The invention relates to a device for selectively positioning at least one cylinder in a printing machine, the cylinder being rotatably mounted in a carrier and, together with the carrier, forming a unit adjustable into different positions, and to a method for operating a printing machine including a positioning device and a cylinder that is adjustable into different positions along an adjusting path, the adjustable cylinder cooperating with a cylinder for guiding printing material or stock.
Positioning devices of this type are used to adjust the cylinder into an operating position and into a rest or maintenance position within the printing machine.
A coating device for printing machines is described, for example, in U.S. Pat. 4,617,865. The device includes a frame that is movable on rails and has a feed roller. The frame is drivable by a ball-screwthread transmission having ball-screwthread nuts which are rotatively drivable by a motor via a link chain. The ball-screwthread nuts, the motor and the link chain are mounted in the frame and are movable together with the latter. The frame and the cylinder are not held by the link chain.
Furthermore, the German Pat. Document DE 69022419 T2 that corresponds to U.S. Pat. 4,934,305 describes a further coating device with a retraction device in the form of a winch for retracting the coating device. A form-paired or paired-form pulling or tensioning device, i.e., paired as to form or shape, such as a chain or a toothed belt, is not provided in this reference.
The aforedescribed positioning devices are well suited for their respective applications, but cannot be used for other applications.
It is accordingly an object of the invention, therefore, to provide a further positioning device for use in printing machines, that provides added advantages to those of the positioning device heretofore used therein.
It is a further object of the invention to provide a method with time-optimized method steps for operating the printing machine including the positioning device and for putting the positioning device into operation, respectively.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a device for selectively positioning at least one cylinder in a printing machine, the cylinder being rotatably mounted in a carrier and, together with the carrier, forming a unit that is adjustable into different positions, comprising a pull mechanism drive for adjusting one of the cylinder and the unit into the different positions, the pull mechanism drive including a pull mechanism, the unit being held on and suspended from the pull mechanism.
In accordance with another feature of the invention, the pull mechanism drive is a form-paired pull mechanism drive.
In accordance with a further feature of the invention, the pull mechanism drive is a chain drive.
In accordance with an added feature of the invention, the pull mechanism is a link chain.
In accordance with an additional feature of the invention, the positioning device includes a spring connecting an end of the pull mechanism to the carrier.
In accordance with yet another feature of the invention, the positioning device includes at least two wheels for guiding the chain drive, the wheels being form-paired with the chain drive.
In accordance with yet a further feature of the invention, the cylinder is an applicator cylinder for applying a coating to a printing material.
In accordance with yet an added feature of the invention, the positioning device includes at least another cylinder rotatably mounted in the carrier.
In accordance with yet an additional feature of the invention, the positioning device includes a guide whereon the carrier is seatable.
In accordance with still another feature of the invention, the guide is formed as at least one roller whereon the carrier is seatable.
In accordance with still a further feature of the invention, the carrier is liftable and lowerable together with the cylinder through the intermediary of the pull mechanism drive in a linear and an approximately vertical direction of motion selectively into the different positions.
In accordance with another aspect of the invention, there is provided a printing machine including at least one positioning device having at least one of the foregoing features.
In accordance with a concomitant aspect of the invention, there is provided a method for operating a printing machine having a positioning device with a cylinder that is adjustable into different positions along an adjustment path and cooperating with a cylinder for guiding printing material, which comprises performing at least two of the following method steps a) to d), including performing the two method steps at least partly simultaneously:
a) adjusting the rotational angle of the cylinder guiding the printing material into a given position;
b) adjusting the rotational angle of the cylinder that is adjustable along the adjustment path into a given position;
c) adjusting the circumferential register of the cylinder that is adjustable along the adjustment path; and
d) adjusting the cylinder that is adjustable along the adjustment path, from a first cylinder position into a second cylinder position along the adjustment path, with the aid of the positioning device.
The device described in the published German Patent Document DE 69022419 T2 can preferably be equipped for circumferential and lateral register adjustment in order to allow accurate positioning of the plate. No method of operating the printing machine including the device is indicated. The chronological course of the adjusting operations required for putting the device into operation is not optimized, and the time required for setting up cannot therefore be reduced.
Thus, the device for positioning at least one cylinder selectively in a printing machine, the cylinder being rotatably mounted in a carrier and, together with the carrier, forming a unit that is adjustable into different positions, includes a pull mechanism drive that adjusts the cylinder or unit into position and has a pull mechanism, the unit being held on and suspended from the pull mechanism.
The unit can be suspended from and held, respectively, on the pull mechanism so as to be completely free, e.g., in a manner comparable to that for an elevator, or with additional guidance, lying, for example, on a sloping plane. The pull mechanism can be a chain or a cable or a belt, and can be secured on the carrier and be a finite pull mechanism. Preferably, the pull mechanism drive is motor-driven.
An advantageous embodiment, which represents a further development of the device according to the invention, calls for the pull mechanism drive to be a form-paired or paired-form pull mechanism drive and, in particular, a chain mechanism.
The category of pull mechanism drives includes not only cable winches and frictionally acting V-belt mechanisms, for example, but also paired-form pull mechanism drives in which a drive and/or guide wheel and the pull mechanism formlockingly engage in one another.
The category of paired-form pull mechanism drives includes not only toothed-belt mechanisms with toothed wheels engaging in the toothed belts but also the preferred chain mechanisms with chain wheels engaging in the chain.
The paired-form pull mechanism drives permit very accurate positioning of the unit and the adjustment thereof over a comparatively large adjustment travel distance.
In a further embodiment, the pull mechanism is a link chain.
In link chains, the individual chain links are connected to one another articulatedly, as is the case, for example, with roller chains.
In a further embodiment, one end of the pull mechanism is connected to the carrier by a spring.
The carrier and the unit, respectively, preferably form an intermediate member which connects the two ends of the pull mechanism. In this regard, the pull mechanism is a finite pull mechanism that does not revolve. A first end of the pull mechanism can hold the unit from above and be connected to or secured on the carrier in an unsprung manner. The second end of the pull mechanism can be connected to a resilient element, e.g., a tension spring, that forms an intermediate member between the second end of the pull mechanism and the carrier and is secured on the carrier. The second end of the pull mechanism can, for example, be connected to one end of a helical spring, the other end of the helical spring being secured on the carrier. In this way, that end of the pull mechanism which does not lift the unit can be suspended and adjusted in a sprung manner on the carrier. However, the pull mechanism can also be a revolving, endless pull mechanism, e.g., a continuous toothed belt.
In a further embodiment, the pull mechanism is guided by at least two wheels. The pull mechanism preferably extends over more than two wheels. The wheels engage formlockingly in the pull mechanism and can, for example, be toothed wheels or chain wheels. In this regard, it is noted that a formlocking connection is one that connects two elements together due to the shape of the elements themselves, as opposed to a forcelocking connection that locks the elements together by force external to the elements. It is further noted that one of the wheels can be driven and can drive the pull mechanism. The wheels guide the pull mechanism and can deflect it into a different travel direction, for example.
In a further embodiment, the cylinder is an applicator cylinder for applying a coating to a printing material.
The coating can be a powdered toner or, preferably, a coating liquid, e.g., a printing ink or a varnish.
The applicator cylinder can be a printing cylinder, e.g., a rubber blanket or printing-plate cylinder, or a varnishing cylinder, e.g. a varnishing-blanket or varnishing-plate cylinder. Rather than being an applicator cylinder, however, the cylinder can be a processing cylinder fitted with tools for processing the printing material and can, for example, be a cutting, creasing, perforating, stamping, smoothing, cleaning or embossing cylinder.
In a further embodiment, at least one further cylinder is rotatably mounted in the carrier.
The cylinder and the further cylinder mounted in the carrier are preferably arranged so as to be axially parallel to one another and in circumferential contact with one another or so as to have a very small spacing between the circumferential outer surfaces thereof. For example, the cylinder can be an applicator cylinder and the further cylinder can be a metering, dipping or anilox roller that is associated with the applicator cylinder and feeds the coating liquid to the applicator cylinder.
In a further embodiment, the carrier can be placed onto a guide.
The carrier and the unit, respectively, can be lowered by the pull mechanism and, in the process, placed onto the guide and lifted again from the latter. In this case, the guide can act like a stop against which the unit strikes during a substantially vertical adjustment downwards, for example. The guide can, for example, be in the form of rails onto which the carrier can be placed.
In a further embodiment, the carrier can be placed on at least one roller acting as the guide.
The roller can be formed as an eccentric roller that is rotatable about an off-center eccentric bearing. The eccentric roller or another roller onto which the unit can be placed can also be formed as a roller pivotable about a pivot bearing.
In a further embodiment, the carrier can be lifted and lowered together with the cylinder by the pull mechanism in a linear and exactly or almost vertical direction of motion into position, selectively.
This embodiment is very advantageous with regard to the accessibility of the unit comprising the carrier and the cylinder and with regard to the installation space required if the positioning device is part of a finishing unit processing or coating the printing material and is, for example, integrated into a varnishing unit.
The device according to the invention can be used in rotary printing machines which print web-like or sheet-like printing material and can be formed as an offset printing machine.
As noted hereinbefore, the method for operating a printing machine, in particular, a printing machine with a positioning device constructed as described hereinabove, which includes a positioning device having a cylinder that is adjustable into various positions along an adjustment path and cooperates with a cylinder guiding printing material, comprises at least two of the following method steps a) to d), the two method steps being performed at least partly simultaneously:
a) adjusting the rotational angle of the cylinder guiding the printing material into a specific position;
b) adjusting the rotational angle of the cylinder that is adjustable along the adjustment path into a specific position;
c) adjusting the circumferential register of the cylinder that is adjustable along the adjustment path; and
d) adjusting the adjustable cylinder from a first cylinder position into a second cylinder position along the adjustment path, using the positioning device.
The adjustable cylinder is preferably movable into the respective positions along a linear adjustment path. In this case, the device according to the invention can be used with the pull mechanism for performing the method. However, the method can furthermore also be used in printing machines which have a positioning device formed in some other way. For example, the cylinder can be pivoted into the corresponding positions by a positioning device of this type. The advantages of the method according to the invention result from the chronological overlap or parallel progress of a number of actuating operations needed to put the printing machine into operation. It is preferable if different drives of the printing machine, driving individual actuating or adjusting processes a) to d) are controlled by an electronic control device so that they are coordinated with one another, and chronologically with the method steps to be performed.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a positioning device in a printing machine, and method of operation, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: